Silent killer: Melioidosis hides in plain sight

In 2018, Dixit Kundar, a young resident of the Udupi district in Karnataka, paid a huge price for a game of barefoot football in rainy July. The only son of his parents Jai and Pathima, he was admitted to Manipal’s Kasturba Medical Hospital with complaints of high fever, severe headaches, repeated vomiting and trouble with closing his eyes while asleep. Despite medical interventions, his condition worsened as the days passed.

A week after being hospitalised, he succumbed to Melioidosis—a condition that was considered rare at the time. The news sent shockwaves through the public and medical fraternity. Following Kundar’s death, health officials were alarmed by the widespread presence of the causative bacterium, Burkholderia pseudomallei, in the soil, water, and environment of tropical, coastal, and monsoon-prone regions in India.

The bacterium is transmitted through inhalation, small cuts, or ingestion of contaminated water. Kundar had played football in flooded areas near his home, and it is suspected that he may have fallen into a waterlogged field during the game, thus exposing him to the disease.

A 2016 report estimated over 50,000 people contract Melioidosis annually in India, with more than 30,000 deaths. “India was predicted to have the highest burden for the disease (20,000- 52,000 new cases/year with an estimated mortality of 32,000 per year),” reads a 2019 bulletin from the National Centre for Disease Control. Troublingly, over 90% of the total cases in the country have been reported in the last ten years, even as academics predict that since 2005, the incidence of the disease has been underreported owing to misdiagnosis. Globally, the disease affects around 160,000 people each year, causing approximately 89,000 deaths.

Rapid response

Microbiologists believe Burkholderia pseudomallei has been prevalent in India for over a century; it was first described in Myanmar’s Yangon in 1911. “Dixit's death brought attention to a deadly infectious disease that the medical fraternity has issued warnings about since 2005,” says Prof Chiranjay Mukhopadhyay, Director of the Manipal Institute of Virology, who identified the first cluster of cases in 2007.

“It invades cells and destroys them. The infection can be particularly fatal for individuals with diabetes and chronic kidney disease. If left undiagnosed and untreated, patients may succumb within 48 to 72 hours,” Mukhopadhyay adds.

Understanding how India’s geography influences the spread of Melioidosis is critical for developing region-specific prevention strategies.

Fearing an outbreak, a team led by Mukhopadhyay visited every household in Udupi to assess the situation. They collected soil samples, tested drinking water sources, and disinfected stagnant water bodies with bleaching powder, in collaboration with district health authorities. They also urged residents to keep their homes, gardens, and cattle stables clean, as well as advising them to wear shoes when working with soil and water.

Those who work on farms, or even engage in recreational activities in waterlogged areas, are at a higher risk of contracting Melioidosis, warn medical experts. Gardening without gloves, walking barefoot, and consuming contaminated water also increase the risk of infection.

Diagnostic challenges

The disease can appear in a manner similar to pneumonia, septicemia, or acute bone and joint infections during the rainy season. In contrast, in the dry season, patients often present with multiple abscesses and skin ulcers.

For years, microbiologists struggled to diagnose Melioidosis due to symptoms that resemble those of common infections such as malaria, tuberculosis, dengue and the flu. This often led to misdiagnoses and delayed treatment. “A delay in identifying the disease can be fatal, as the infection requires specific antibiotic treatment,” Mukhopadhyay explains.

That Melioidosis can remain dormant in the body for years, resurfacing only when the immune system weakens, only adds to the concerns surrounding its diagnosis. “This characteristic makes it a ‘silent killer’ that can strike without warning. The disease can lie undetected for long periods, posing a persistent and hidden threat,” he said.

Environmental conditions

India's tropical, coastal, and monsoon-affected regions provide ideal conditions for the growth and spread of Burkholderia pseudomallei. While cooler, arid, and high-altitude areas face a lower risk, factors such as flooding, irrigation, and poor sanitation still pose significant threats.

Scientists have found connections between climate change and the spread of Melioidosis—including rising temperatures and more extreme weather events; Burkholderia pseudomallei thrives in warm, humid environments. Higher temperatures and lingering moisture create the perfect habitat for the bacteria in soil. As rainfall and flooding increase, the bacteria migrates from soil to water sources, broadening its spread.

Human intervention, in the form of deforestation, urbanisation, and changes in agricultural practices, also contribute to the spread of the disease. Soil disturbances during the rainy season, combined with strong winds, can release the bacteria into the air, raising the risk of inhalation and infection.

Climate change-induced extreme weather events, such as cyclones and droughts, can significantly alter the dynamics of Burkholderia pseudomallei in the environment. Cyclones bring heavy rainfall and soil erosion, while droughts concentrate the bacterium in soil and water, increasing its virulence during subsequent periods of rainfall. “Understanding how India’s geography influences the spread of Melioidosis is critical for developing region-specific prevention strategies. On the climate change front, raising awareness, improving surveillance, and adopting sustainable practices are essential measures to combat the threats posed by Melioidosis,” Mukhopadhyay says.

Preventive action

To combat the disease's spread, the Indian Council of Medical Research (ICMR) launched MISSION: A Multi-Centric Capacity Building Initiative to Strengthen the Clinical and Laboratory Detection of Melioidosis in 2022. The project involves 15 medical centres across 14 states, including Arunachal Pradesh, Assam, Sikkim, Tripura, Manipur, Meghalaya, Mizoram, Nagaland, Karnataka, Kerala, Madhya Pradesh, New Delhi, Odisha and Rajasthan. The initiative aims to raise awareness about Melioidosis and improve early detection and treatment protocols.

Kasturba Medical College (KMC) in Manipal, a leader in Melioidosis research for the past two decades, serves as the referral centre for the project. The Centre for Emerging and Tropical Diseases (CETD) has developed comprehensive training protocols for healthcare staff, equipping doctors and technicians with the tools needed to diagnose and treat the disease effectively. “Accurate diagnosis is critical for the successful treatment of Melioidosis. This capacity-building initiative aims to empower healthcare facilities across India to identify and manage the disease more efficiently,” Mukhopadhyay informs.

Early diagnosis is essential for effective treatment. “If the diagnosis is delayed, doctors may administer broad-spectrum antibiotics indiscriminately, potentially leading to antimicrobial resistance. This makes proper treatment increasingly difficult. Early and accurate diagnosis is, therefore, vital,” the veteran microbiologist explains.

Greater awareness can be raised if Melioidosis were classified as a notifiable disease, as well as recognised as a neglected tropical disease, he adds. This recognition will increase public awareness and help experts to attract funding and conduct research to combat it. “With the rising number of cases, particularly in tropical regions, we must invest in understanding the disease and developing effective treatments. By categorising it as a notifiable and neglected tropical disease, we can ensure the necessary resources are allocated to combat it, ultimately reducing its impact on affected populations,” he concludes.

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